Session Initiation Protocol (SIP) is a call control signaling protocol for Internet Protocol (IP) networks. SIP is designed to be device-agnostic—that is, it is intended to provide a highly flexible call signaling capability that is not tailored to the capabilities of any particular device and/or vendor. Many call center software solutions are not device-agnostic or vendor-agnostic, and may require that the same vendor and/or devices are used throughout the network to maintain proprietary protocols.